5 Things to Watch

It’s a rather quiet start to the new week across the Lower 48 overall. However, activity should ramp up as the week progresses, especially as we monitor a developing nor’easter this coming weekend. We’re tracking that and more in this week’s 5 Things to Watch.

Willa to Bring Heavy Rain to Gulf Coast:

Hurricane Willa, an extremely dangerous Category 4 storm, will make landfall on Tuesday on the western Mexican coast as a major hurricane. Despite the storm being located over the eastern Pacific Ocean, a portion of the US will actually be impacted by its remnants. As the leftovers of Willa move to the north and east following landfall in Mexico, its moisture will meet up with a distance tracking east across the US, bringing heavy rain to parts of the southern Plains and Gulf Coast midweek. A low pressure will then form over the Southeast late-week, eventually transitioning into this season’s first nor’easter off the Eastern Seaboard (more on this below). Before this though, localized flash flooding will be possible in Texas eastward through Florida as several inches of rain possibly comes down as a result of Willa’s remains.

High precipitable water totals along Gulf Coast, as shown in the 0z ECMWF model run

First Fall Front:

All of Florida has finally experienced its first cold front of the season, signifying additional changes to come. In the summertime it is a rarity if not unprecedented for a cold front to sweep through the entire state. This becomes more common, however, in the colder months. Typically, the first front clears through Florida in early October, but it has taken the latter part of the month this year for that to take place. Now that the first front has pushed through as of Sunday night, the air is noticeably drier (especially in the northern half) while temperatures are cooler. Miami had a record daily high temperature of 91 degrees on Sunday–this Monday it will be about 10 degrees cooler. 1 to 2 additional cold fronts are expected to hit the state this week.

Warm West, Chilly East:

Fall — and in some cases winter — is in the air across the eastern US while the West enjoys temperatures warmer than average. This comes as a new, significant dip in the jet stream takes place midweek across the country, allowing for widespread temperatures of 5 to 15 degrees below normal in the East and the complete opposite out West. In some areas, it’s going to be unusually cool, causing daily record low maximums (record cold high temperatures) to take place for the Northeast around this coming weekend. The only region in the East that will not really feel this cool down will be South Florida since the air will moderate before reaching coming down south.

High temperature anomalies for Thursday

Tropics Quiet:

September into October was quite active in the Atlantic basin, and activity for the year is officially above average in terms of both the number of named storms and the Accumulated Cyclone Energy. With just over a month left of hurricane season, the basin has become dead for about a week now. There was an invest that ran out of time before it impacted Central America last week, but since then there hasn’t been much to monitor. This trend should continue through the remainder of the season, but an additional cyclone cannot be ruled out based on history.

Season’s First Nor’easter:

The first nor’easter of the season will likely to develop this weekend, signaling a change in seasons and a sign of what’s to come in the months ahead. The exact track and intensity of this low pressure is still uncertain, but the most likely outcome at this time is for heavy rain and gusty winds to affect much of the Northeast coast and really most of the East Coast. Some snow falls will be seen in the higher elevations of the central and northern Appalachian Mountains of the MId-Atlantic and Northeast thanks to cold air funneling in from the north. We will continue to provide updates and forecasts for this potential Nor’easter as model guidance progresses throughout the week and we get a better idea of what exactly is coming.

For a more in-depth discussion on this nor’easter, check out this week’s Sunday Storm.

Jackson is Head of Content at WeatherOptics and produces several forecasts and manages all social media platforms. Previously, Jackson forecasted local weather for southwestern Connecticut, founding his website, Jackson's Weather, in the March of 2015. He is currently studying Meteorology and Broadcast Journalism at the University of Miami.